Multiple-action loaf slicing machine



Feb. 19, 1963 w. w. HARTMAN 3,077,910

MULTIPLE-ACTION LOAF SLICING MACHINE Filed July 12. 1960 4 Sheets-Sheet1 W/u mm .WHHITMFM/ Feb. 19, 1963 w. w. HARTMAN MULTIPLE-ACTION LOAFSLICING MACHINE 4 Sheets-Sheet 2 Filed July 12. 1960 INVENTOR. 5421/4 14WAQeTMflA/ Feb. 19, 1963 w. w. HARTMAN MULTIPLE-ACTION LOAF SLICINGMACHINE 4 Sheets-Sheet 3 Filed July 12. 1960 3,077,910 MULTWLE-ACTIONLOAF SLICING MACHlNE William W. Hartman, 418 S. June St., Los Angeles,Calif. Filed July 12, 1960, Ser. No. 42,288 7 Claims. (Cl. 146-88) Thisinvention deals generally with slicing machines of the type adapted toslice loaves of bread and the like and, more particularly, with a uniquemultiple-action, loaf slicing machine which substantially increasesproduction and saves valuable floor space in todays crowded commercialbakeries.

Reference is made herein to my prior U.S. Patent No. 2,759,510 entitledFeed Mechanism for Bread Slicing Machine issued August 2.1, 1956.

In the loaf slicing and wrapping art as presently practiced, each loafslicing machine consist sof a series of horizontally spaced knives whichare moved longitudinally either in a vertical direction or in adirection inclined slightly from the vertical and a single feedmechanism for feeding the loaves to be sliced to and through a singleslicing zone of the knives. Each slicing machine serves only a singlewrapping machine.

The output of a slicing machine of this type can be increased only byincreasing the rate of travel of the loaves through the machine. Thismethod of increasing output is unsatisfactory since it involves muchmore rapid operation of the machine components, which complicates theinitial machine design and subsequent machine maintenance, and, perhapsmore important, the increased operating speeds result in damage to theloaves or unsatisfactory slicing thereof.

A general object of this invention is to provide a new and improved loafslicing machine in which one slicing mechanism is made to serve aplurality of infeed mechanisms and a plurality of wrappers, therebydoubling or tripling the total output of the slicing mechanism withoutappreciably increasing its overall cost.

A more specific object of the invention is to provide a multiple-action,loaf slicing machine of the character described which is characterizedby a plurality of parallel loaf feeding mechanisms arranged along acommon set of slicing knives so that the loaves handled by the differentfeed mechanisms are sliced in different slicing zones of the sameslicing knives.

Yet another object of the invention is to provide a multiple-action,loaf slicing machine of the character described in which the severalloaf feed mechanisms are driven in synchronism from a common drive meansin such a way that a loaf is sliced in only one slicing zone at a timeso as to avoid undue loading and flexing of the slicing knives.

A further object of the invention is to provide a mult iple-action, loafslicing machine of the character described embodying a shiftableconveyor means for selectively transferring loaves to be sliced from asingle infeed conveyor belt to the different loaf feeding mechanisms ofthe machine.

Yet a further object of the invention is to provide a multiple-action,loaf slicing machine of the character described which is used inconjunction with a multiple-action, loaf wrapping machine consisting ofseparate Wrapping mechanisms, each of which receives and wraps thesliced loaves from a respective slicing zone of the slicing machine.

Other objects, advantages and features of the invention will becomereadily apparent as the description proceeds.

Briefly, the objects of the invention are attained in the illustrativeembodiment thereof by providing a loaf slicing machine equipped with apair of parallel loaf feeding mechanisms mounted :one over the other ona common fname and along a common set of slicing knives in such PatentedFeb. 19, 1963 a way that theupper feed mechanism moves its respectiveloaves against an upper portion or slicing zone of the knives and thelower feed mechanism moves its loaves. against a lower portion orslicing zone of the knives. The

loaves sliced in these upper and lower zones are conveyed to twoseparate wrapping mechanisms arranged one over the other. Preferably,the two loaf feeding mechanisms of the slicing machine and the Wrappingmechanisms are driven in synchronism from a common drive means in such away that loaves are sliced alternately in the two slicing zones. In thisway, undue loading and flexing of the slicing knives is avoided.

The illustrative two level construction of the present loaf slicingmachine should be regarded as being merely illustrative and not limitingin nature. That is to say, the slicing machine of this invention mayhave as many as three or even more slicing levels, depending upon thedesired total output. With three or more slicing levels, loaves arepreferably sliced successively or alternately in the several slicingzones to avoid undue loading and flexing of the slicing knives.

The highly import-ant advance in the art achieved by this invention,namely, that one slicing mechanism is made to serve a plurality of loaffeeding mechanisms and a plurality of wrappers, thereby doubling ortripling the total output of the mechanism with only a. slight increasein the cost of the overall slicing machine, and at the same timeminimizing floor space requirements, results, primarily, from the use ofone particular form of existing slicing mechanism which is uniquelyadapted to the pres-= ent multiple slicing action. This well-known typeof slicing mechanism consists of a multiplicity of parallel bladesmounted side by side with their cutting edges substantially in the sametransverse plane and with the adjacent blades moving in oppositedirections.

It will become apparent as the description proceeds that the inventiondoes not consist merely in placing one slicer on top of or besideanother slicer and one wrapper on top of or beside another wrapper andthen interbuilding them into one frame forthe purpose of doubling theoutput. This type of construction would result in an extremely complexand commercially impractical slicing.

machine.

The illustrative embodiment ofthe invention will now be described indetail by reference to the attached drawings, in which:

FIG. 1 is a view, in side elevation, of a double-acting loaf slicingmachine and wrapping machine according to the invention;

FIG. 1a is an enlargement'of the area encircled by arrow 1a in FIG. 1;

FIG. 2 is an enlarged view, in side elevation, of the internal mechanismof the slicing machine in FIG. -1;

FIG. 3 is a view looking in the direction of the arrows on line 3-3 ofFIG. 2;

FIG. 4 is a view looking in the direction of thearrows on line 4-4 inFIG. 2;

FIG. 5 diagrammatically illustrates, on a further enlarged scale, thealternate slicing action of the slicing machine;

FIG. 6 is a timing diagram of the machine;

FIG. 7 is a somewhat exaggerated perspective view of a single band bladeshowing the manner of mounting and twisting the blades with respect tothe drums; and

FIG. 8 is a view of the drums and-multiplicity of blades thereon takenas indicated by the arrows 88 on FIG. 7.

aforementioned U.S. Patent No. 2,759,510. Accordingly,

the parts of the present machine which are similar to those of the priormachine will be only briefly discussed herein. If additional descriptionof these parts is desired, reference should be had to the patent.

The slicing machine 20 comprises a main frame structure 22 including anupper inclined housing extension 24 enclosing the slicing mechanism 26.As preliminarily mentioned, one particular well-known type of slicingmechanism is especially well suited for use in the machine, namely, oneconsisting of a plurality of parallel blades or knives mounted side byside with their cutting edges substantially in the same transverse planeand with the adiacent knives moving in opposite directions. Slicingmechanisms of this general character are illustrated in US. Patents Nos2,143,242, 2,173,038 and 2,424,659.

For simplicity, the slicing mechanism 26 illustrated in the presentdrawings is of the type disclosed in U.S. Patent No. 2,424,659 andincludes a plurality of endless cutting bands or blades 28 which aretwisted into the usual figureeight arrangement and trained aboutsupporting and guiding rolls or drums 3% past guide means 31. The lattermay consist of pairs of guides 31 so that in the zone Z1, between thepair of lower guides 31, and in the zone Z2, between the pair of upperguides 31, the bands or blades 28 are parallel and have their cuttingedges substantially in a common transverse plane Pli which is parallelto the guiding rolls 3t) and is inclined slightly from the vertical.Since these blades are located one behind the other in the drawings,only the forward blade 28 is visible. For more detailed drawings anddescription of one form of the parts described in this paragraph, thereader is referred to my previously mentioned United States Patent No.2,424,659, dated July 29, 1947, particularly FIGS. 1, 2 and 3 of thedrawings thereof and also the written description thereof. Themultiplicity or group of endless cutting bands 28 of this presentapplication are shown as the bands or strands 14 and 15 of said patent;the two sets or pairs of spaced guiding rolls 3% of this application areindicated by parts 16 and 12, both together comprising one set or pairof such rolls, and by parts 11 and 13 together comprising the other setor pair of such rolls, in said patent; and the said guide means 31 ofthis application is indicated by one of the two guides or parts 22 insaid patent. All these parts are shown in either FIGS. 1, 2 or of thisapplication, but they are shown larger and more clearly in said patent,as just referred to.

While the layout of a slicing machine embracing my invention, can beleft to the wishes of the designer, I wish to point out that in thepreferred form of my slicing machine I prefer the arrangement of theguide rolls 3t), and of the cutting bands 23, to be more or less asshown in FIG. 1 of this present specification, wherein the cutting bandsoccupy a more or less upright, though inclined, position or direction asshown in said FIG. 1. This is brought about by having one set or pair ofguide rolls 39 located higher than the other set or pair of such guiderolls 30, and this general arrangement of the guide rolls and cuttingbands obviously permits the loaf feeding mechanism 34 and 32, FIGS. 1and 2 hereof, to be located one higher than the other along the cuttingbands as shown in said figures; and of course this permits thecorresponding and hereinafter described wrapper parts 52 and 50 ofFIGURE 1, to be similarly located at successively higher elevations withrespect to each other. All this in turn is of considerable importance inthe large modern bakeries, in that it permits the total slicing andwrapping apparatus to be very compact and concentrated in the sense thatit utilizes the available floor space in such bakeries very efiicientlyin comparison with any other slicing apparatus now available. That is,with my arrangement as just described, substantially more loaves can besliced and wrapped for each square foot of floor spaced allotted to thispurpose, than with any other arrangement of slicers or wrappers nowknown, and this is of prime importance to the larger bakeries now usingthis kind of equipment because in many of them, and for various reasons,the operating conditions are today quite congested in the generalvicinity of the slicers and wrap pers, and floor space is at a premium.Therefore, in concluding this part of the description, I wish to pointout that my invention serves the double purpose of multiplying theproduction of the slicer at a disproportionately small increase in thecost of the slicer, and at the same time of producing such compactnessin the slicer and the wrapper as to substantially relieve the congestionusually found in the bakeries around the slicers and wrappers. Theadvantages of achieving at one stroke, this double purpose or benefit,need not be further emphasized.

The primary improvement feature of the present slicing machine residesin the provision of two separate loaf feeding mechanisms in the machine,namely, a lower feed mechanism 32 and an upper feed mechanism 34- whichare mounted one over the other on the frame 22 and having deliveryportions to said cutting bands 28 between said guide means. As willpresently be more fully described, these feed mechanisms operate toalternately convey loaves to be sliced through the two vertically spacedzones Z1 and Z2, hereinafter referred to as slicing zones, of the sameslicing mechanism 26.

The loaves to be sliced are conveyed to the slicing machine 20 on asingle horizontal conveyor belt 36. Located between this conveyor beltand the slicing machine is a transfer conveyor 38 which receives loavesfrom the conveyor 36. The end of the transfer conveyor, adjacent themain conveyor, is hinged on an axis 40 for vertical swinging of theother end of the transfer conveyor 38 between its solid line position ofFIG. 1, wherein it delivers loaves to the upper feed mechanism 34 of theslicing machine, and its phantom line lower position, wherein itdelivers loaves to the lower feed mechanism 32 of the machine.

The transfer conveyor is moved between its upper and lower positions inany suitable way, such as by hand, or by means of a cam 42 whichvertically moves a cam follower rod 44, pivotally connected at its upperend to the free end of the transfer conveyor 38, and is driven insynchronism with the slicing machine 20 through a chain drive 46 and areduction gear unit 48. Cam 42 is, therefore, slowly rotated insynchronism with operation of the slicing machine 20 and has theconfiguration illustrated which erTects retention of the transferconveyor 38 in its upper position for one-half of a cam revolution andin its lower position for the other half of the cam revolution.

The main conveyor belt 36 is driven at approximately twice the averagespeed at which loaves are conveyed through each of the upper and lowerlevels of the machine by the upper and lower feed mechanisms 34 and 32so as to maintain a constant supply of leaves to the machine sufiicientto keep both the upper and lower levels of the machine filled. Thetransfer conveyor 38 is driven by a motor 49, at a somewhat greaterspeed than conveyor 36, and is energized through a switch 49a, operatedby a cam 49!; on the side of cam 42, which opens the switch to stop thetransfer conveyor 38 when the latter is being shifted up or down andrestart it when it reaches its upper or lower position.

Located behind the slicing machine 20, that is, to the right of themachine as it is viewed in FIG. 1, are two wrapping mechanisms 5t) and52 which are mounted one over the other, as shown. As will be shortlymore fully described, the lower wrapping mechanism 50 receives and wrapsthe sliced loaves from the lower level of the slicing machine. The upperwrapping mechanism 52 receives and wraps the sliced loaves from theupper level of the slicing machine. These wrapping mechanisms may be ofany conventional type and are operated in synchronism from a commondrive means 54. This drive means also drives a power take-oft shaft 56from which the slicing machine 2% is operated in synchronism with thewrapping mechanisms, as will presently be described.

The lower loaf feeding mechanism 32 is driven by a drive mechanism 58which also drives the upper feed mechanism 34. The mechanism of thelower level of the machine, comprising the lower feed mechanism 32 andthedrive mechanism 58,-is identical in many respects to'the mechanism ofmy prior slicing machine. For this reason, as already noted, thefollowing description of these parts will be abbreviated, it beingunderstood that if additional details of the same are required,reference may be had to my patent.

The lower loaf feeding mechanism 32 comprises a first intermittentlyoperated infeed conveyor belt 66, a second fast, continuously travelingendless conveyor 62, preferably constituted of' a plurality of spacedsprocket chains 64, a third, continuously operating pusher conveyor unit66, a fourth, continuously operating outfeed conveyor belt 68, stepfingers 70 which are periodically retracted to permitmovement of theloaves to be sliced from the fast conveyor 62 to the conveyor unit 66,and a loaf holddown or stabilizer 71 These several components of thelower loaf feeding mechanism are operated in synchronism, by the drivemechanism 58,- in the manner to be hereinafter briefly discussed, tofeed the lower row of loaves a to be sliced to and through the lowerslicing zone Z1 of the slicing machine.

Drive mechanism 58 includes a main, continuously and uniformly rotatingdrive shaft 72, which is driven from the power take-off shaft 56 of themain drive means 54, through sprocket chains 74 and 76, and a seconddriven shaft 78, which is driven from shaft 72 through a sprocket chain80. The second, fast conveyor 62 and the fourth, outfeed conveyor belt68 are driven directly from shaft 78 through sprocket chains 82 and 84,respectively. Mounted on the forward end of shaft 78 is a first crankarm 86, to the outer end of which is pivotally connected the connectingrod or arm 88 that actuates the ratchet mechanism 90 for intermittentlydriving the infeed conveyor belt 60. The conveyor unit 66 is driven, viaa sprocket chain M, from shaft 78 of the drive mechanism.

The upper loaf feed mechanism 34 is carried on an upper table 92 mountedover the lower table 94 which is apertured to receive the lower infeedconveyor belt 69. This upper feed mechanism is identical to the lowerfeed means and comprises a first intermittently operated infeed conveyorbelt 96 located within an aperture in the upper table 92, a second fast,continuously traveling endless conveyor 93 consisting of a plurality ofspaced sprocket chains 9?, a third, continuously operating pusherconveyor unit 100, a fourth, continuously traveling outfeed conveyorbelt Hi2, stop fingers 164 which are periodically retracted to permitmovement of loaves to be sliced from the fast conveyor 98 tothe-conveyor unit 1%, and a loaf holddown or stabilizer 1G6.

Theinfeed conveyorbelt 96 is intermittently operated by a ratchetmechanism 1% identical in construction and operation to the lowerratchet mechanism 90 which operates the lower infeed conveyor belt 63.This upper ratchet mechanism is located at the opposite side of themachine frame 22 from the lower ratchet mechanism, i.e., the read sideof the frame as the machine is viewed in FIG. 2. As shown best in FIG.4, the shaft 110 of the upper mechanism is journaled in a bearing 111located at the underside of the upper table 92 and carried on a verticalsupporting member 112 for the upper table.

The upper ratchet mechanism is actuated by a connecting rod or arm 114,the lower end of which is pivoted to the outer end of a second crank arm116 fixed on the rear end of shaft 73 in the lower drive mechanism 58,as the latter is viewed in FIG. 2.

Crank arms 86 and 116 are displaced 180, as may be best observed in PEG.2. As a result, during rotation of shaft 78, in the drive mechanism 53,through one-half of a revolution, the connecting rod 11 is moveddownwardly to actuate the upper ratchet mechanism 1193 and therebyadvance the upper infeed conveyor belt 96 a short distance while thelower connecting rod 88' is moved upwardly to reset the lower ratchetmechanism 99 and the lower infeed conveyor belt 60 remains stationary.During the next half revolution of shaft 73, the upper connecting rod114 is moved upwardly to reset the upper ratchet mechanism while thelower connecting rod 88' is pulled downwardly to actuate the lowerratchet mechanism 9d and thereby advance the lower infeed conveyor belt6t) a short distance. Thus, the upper and lower infeed conveyor beltsare intermittently operated in alternate fashion during operation of themachine.

The second fast conveyor 98, conveyor unit 101 and the outfeed conveyorbelt 192 of the upper feed mechanism 34 are driven from the drivemechanism 58, as follows: The forward end of the sprocket shaft 118 ofthe lower fast conveyor 62, which shaft is driven by the sprocket chain82, and the sprocket shaft 121 of the upper fast conveyor 1% areextended forwardly of the machine, as the latter is viewed in FIG, 2,and mount sprockets 122 and 124, respectively, at their forward outboardends. Trained about these sprockets is a sprocket chain 126 whereby theupper fast conveyor is driven from the driven shaft 118 of the lowerfast conveyor.

Similarly, the sprocket shaft 128 of the lower conveyor unit, whichshaft is driven by the sprocket chain 91, and the sprocket shaft 130 ofthe upper conveyor unit 100 areextended forwardly, as the machine isviewed in FIG. 2, and mount at their forward outboard ends sprockets 132and 134 around which is trained a sprocket chain 136 so that the upperconveyor unit 104) is driven from the driven shaft 128 of the lowerconveyor unit.

Finally, the driven shaft 137 of the lower outfeed conveyor 68, whichshaft is driven by the sprocket chain 84, and the shaft 138 of the upperoutfeed conveyor 192 are extended forwardly and mount sprockets 139 and141) about which is trained a sprocket chain .142 that drives the upperoutfeed conveyor 102 from the driven shaft 137 of the lower outfeedconveyor.

Thus, during operation of the machine, the three lower conveyors 62, 66and 63 and the three upper conveyors 98, 100 and 102 are continuouslydriven in synchronism. As shown best in FIG. 5, the loaf pushing meansor pushers 144 of the lower conveyor unit 66 are displaced from the loafpushing means or pushers 146 of the upper conveyor unit 100, for reasonsto be presently seen. For the purpose of greater clarity in theforegoing description, 1 wish to point out that the loaf pushers 144 inthe lower loaf feeding mechanism, and the corresponding pushers 146 inthe upper or higher loaf feeding mechanism, and their continuouslyoperating endless conveyors hereinbefore mentioned and shown in FIGS. 2and 5 of the drawings herein, are the pushers 111 and their endlesschain conveyor 112 shown in FIG. 3 of my aforesaid United States PatentNumber 2,759,510, dated August 21, 1956, and the latter parts are allthoroughly described in the written specification of said patent towhich attention has been previously directed in this presentspecification.

The lower stop '70 and holddown '71 are operated by a pair of cams 148and 150 fixed on the shaft 78, as described in my prior patent. Theupper stop 1114 and the upper holddown 106 are operated by an additionalcam 152 fixed to the forward end of the shaft 78, just behind the crankarm 86, as the machine is viewed, in FIG. 2. This cam is identical inshape to but is displaced 180 from the cams 148 and 150.

Pivoted to an upstanding bracket 154 on the frame of the machine is acam follower arm 158 mounting a cam follower roll 160 which rides on theperiphery of earn 152. A vertical connecting arm 162 is pivotallyconnected at its lower end to the free end of the cam 7 follower arm 15%and at its upper end to an arm 164 which is rigid on a shaft 166.

As shown best in FIG. 4, shaft 166 is rotatably supported in bearingblocks 16% fixed to the underside of the upper table 92. Firmly fixed atone end to this shaft are a pair of spaced, parallel arms 170, the upperends of which, as the machine is viewed in FIG. 4, underlie the upperfast conveyor 98. Fixed to and bridging these ends of the arms 170 is acrosspiece 172 to which the lower ends of the upper stop fingers 194-are rigidly fixed.

Also rigidly secured at one end to the shaft 166 is an arm 174, to theother end of which is pivoted the lower end of a link 176. The upper endof this link is connected to the upper holddown 166.

When the cam 152 rotates, therefore, the upper stop 104 and the holddown106 are raised and lowered in exactly the same way as the lower stop '70and holddown 71. Since cams 143 and 150 are 180 displaced from cam 152,however, the upper stop and holddown are raised and lowered 180 out ofphase with the lower stop and holddown.

In operation of the present double-action loaf slicing machine, thetransfer conveyor 38 is alternately shifted between its upper and lowerpositions, by operation of its actuating mechanism 42-48, tocontinuously feed loaves to be sliced to the upper and lower levels ofthe machine. Thus, the transfer conveyor, when in its upper positionrapidly feeds a number of loaves to the upper level of the machinesuificient to fill its infeed conveyor belt 96, the loaves sliding alongthe belt to the last loaf then on the belt. The cam 4% then opens switch490 to stop the transfer conveyor, whereupon the latter is lowered, bycam 42, to its lower position and restarted by reclosing of switch 49aby cam 4%. While the transfer conveyor is thus inoperative, it continuesto receive loaves from the main conveyor 36 which close the gapresulting from rapid feeding of the loaves to the upper level. Whenrestarted in its lower position, the transfer conveyor delivers a numberof loaves to the lower level of the machine sufiicient to fill itsinfeed conveyor belt 60, whereupon the conveyor is shifted to its upperposition and the cycle is repeated. As mentioned earlier, the transferconveyor may, if desired, be shifted by hand, rather than automatically.Alternatively, of course, the two levels of the present machine may beloaded by hand.

The operating cycle of each level of the present machine issubstantially identical to that described in my prior patent. Theoperation of the machine as a Whole will now be described by referenceto the timing diagram of FIG. 6 in which position the inner full linecircles are for the lower level of the machine and the outer full linecircles are for the upper level of the machine. Position I of thediagram corresponds to the position of the machine illu-strated in FIG.2. At this time, the lower level of the machine is about to complete itscurrent cycle of operation and start the next cycle, which occurs atposition I Thus, at I, on the timing diagram, the lower stop fingers 70and holddown 71 are elevated by their cams 148 and 150, and the lowerinfeed conveyor 60 is being driven through the last few degrees of itstravel, by its crank 86 and ratchet feed mechanism 90, to advance thestring of loaves d, e and f on the conveyor to a position where thefirst load d engages the elevated stop fingers 7 t3. Loaf c is on thelower pusher conveyor unit 66, about to be engaged by a pusher 144 ofthe unit, and loaf b is being advanced, by the previous pusher 144,against the knives 28 in the lower slicing zone Z1 after having pushedthe first loaf a ahead of it through the knives onto the lower outfeedconveyor 68. Sliced loaf a is carried to and wrapped in the lowerwrapper St). A few degrees later in the cycle, at position 1 the lowerinfeed conveyor 6% comes to a stop, and the pusher 144 engaging loaf breaches the d o its forward travel and drops out of engagement with theloaf leaving the latter in a partially sliced condition part way throughthe knives 2-8.

The upper level of the machine is 180 out of phase with the lower levelof the machine. Accordingly, at position l of the timing diagram, loaf bis being advanced by a pusher 146 of the upper conveyor unit 100, towardloaf a which is stationary and in a partially sliced condition part waythrough the knives 28 in the upper slicing zone Z2 of the machine. Loafc has just been released by lowering of the upper stop fingers 104 andholddown res and is being kicked onto the conveyor unit 160 behind thepusher currently engaging loaf b, by the high speed chains of the upperfast conveyor 98, as shown in FIG. 2.. I

A few degrees later, at position I of the timing diagram, when slicingends in the lower slicing zone Z1 of the machine, advancing loaf b inthe upper level engages the partially sliced loaf a to commence slicingin the upper zone.

Sixty degrees later in the cycle of the machine, at position 1 the lowerstop fingers 70 and holddown 71 have been lowered by their cams 148 and150 to release loaf d, presently on the lower fast conveyor 62,,which-is kicked onto the lower conveyor unit behind the pusher 144 thenadvancing loaf 0 toward the partially sliced loaf b, which is part waythrough the knives 28. At position I, on the timing diagram, 180 awayfrom position I loaf c engages loaf b to commence slicing in the lowerslicing zone Z1 of the machine, as shown in FIG. 5.

in the upper level of the machine, during the half cycle betweenpositions 1 and I, of the timing diagram, loaf b' pushes loaf of onthrough the knives 28 to complete slicing of the latter loaf, whereuponloaf b is pushed against the knives. The pusher of the upper conveyorunit lilil reaches the forward limit of its travel at position 1 of thediagrarnand then drops out of engagement with the loaf b, leaving thelatter part way through the knives, to terminate slicing in the upperzone Z2, as shown in FIG. 5.

At position 1,; of the half cycle under discussion, which is after dwellof the upper stop fingers 104 and holddown 166 in their loweredposition, they are again elevated by earn 152. Shortly thereafter, atposition 1 of the diagram, the crank 116 starts its downward stroke toactuate the upper ratchet mechanism 108 and advance the upper infeedconveyor 96, during the interval between positions I and I of thediagram, which brings loaf :1 against the upper, elevated stop fingers104. The upper infeed conveyor stops at position 1 on the timing diagramto complete a cycle of operation of the upper level of the machine.

It will be recalled that at position I, of the diagram, slicing isterminated in the upper slicing zone Z2, while in the lower level of themachine, advancing loaf cengages the partially sliced loaf b to commenceslicing in the lower slicing zone Z1. Slicing contines until loaf b hasbeen pushed on through the knives 28, to complete slicing of the latterloaf, and the pusher 144- reaches the forward limit of its travel anddrops out of engagement with loaf c after having pushed the latterthrough the knives. This occurs at position 1 of the diagram.

During the latter half of the cycle of the machine, between positions I,and I and after 150 dwell of the lower stop fingers 70 and holddown 71in their lowered position, they are elevated at position 1,, of thetiming diagram. Shortly thereafter, at position L, of the diagram, crank86 commences its downward stroke to actuate the lower ratchet feedmechanism 9% and, again, advance the lower infeed conveyor 60. Thiscontinues to position I; on the diagram, during which loaf e is advancedto the elevated stop fingers 70, whereupon the lower infeed conveyorcomes to a stop to complete another cycle of the lower level of themachine.

In the upper level of the machine, 60 after position I, of the diagram,at position L7, the stop fingers 104 and holddown 106 have been loweredby their cam 152 to release load d which is then kicked onto the upperconveyor unit 100, by the fast moving chains of the unit, behind thepusher 146 which is currently advancing loaf c toward the partiallysliced loaf b'. At position I; of the timing diagram, the advancing loafc' engages loaf b' to commence slicing in the upper slicing zone Z2.

This, then, completes one operating cycle of the machine during whichloaf a was completely sliced, and loaf b was partially sliced in theupper slicing zone Z2 and loaf d was released for movement onto thelower conveyor unit 66 between position I and L; on the timing diagram,and loaf b was completely sliced and loaf c was partially sliced in thelower slicing zone Z1, and loaf c was released for movement onto theupper conveyor unit 100 during the interval between positions 1 and I onthe diagram.

During the next cycle of the machine, loaf b is completely sliced andloaf c is partially sliced in the upper zone of the machine and loaf eis released by the lower stop fingers 70 for movement to the lowerconveyor unit 66 during the interval between positions I and 1 of thetiming diagram. In the last half of the cycle, between positions I, andI of the diagram, loaf c is completely sliced and loaf d is partiallysliced in the lower slicing zone Z1 while, in the upper level of themachine, loaf e is released by the upper stop fingers 104 for movementonto the upper conveyor unit 100.

From the foregoing description, it is evident that in the particularform of feed mechanism shown, loaves are sliced in only one slicing zoneof the machine at any one time. Excessive deflection and loading of theknives 28 is thereby avoided.

It is also obvious that because of the two level construction of thepresent machine, its output is twice that of a conventional singleaction machine while the speed of the parts and the rate of travel ofthe loaves through the machine remain the same as in the single actionmachine. As preliminarily mentioned, the machine may have more than twoslicing levels in which case, of course, the output of the machine isfurther increased. In this case, the several levels are preferablysynchronously operated in such a way that loaves are sliced successivelyin the several slicing zones of the common set of slicing knives inorder to avoid undue loading and flexing of the latter.

It is clear, therefore, that the loaf slicing machine hereinbeforedescribed and illustrated is fully capable of attaining the severalobjects and advantages preliminarily set forth.

While a presently preferred embodiment of the machine is disclosed forillustrative purposes, numerous modifications in the design, arrangementof parts and instrumentalities of the invention are obvious within thespirit and scope of the following claims.

What is claimed is:

1. A machine for slicing loaves of bread and the like, comprising agroup of endless cutting bands having two sets of spaced guiding rolls,at least two spaced guiding means for said bands between said two setsof rolls, the bands between said guiding means being substantiallyparallel, and at least two loaf feeding mechanisms adjacent said cuttingbands and having delivery portions between said guiding means.

2. The subject matter of claim 1, wherein each of the two sets ofguiding rolls comprises a pair of guiding rolls.

3. The subject matter of claim 1, wherein the cutting bands between saidguiding means are side by side and have their cutting edgessubstantially in a common plane extending parallel to said guidingrolls, and wherein adjacent strands of said bands run in oppositedirections.

4. The subject matter of claim 3, wherein one of said sets of guidingrolls is located higher than the other of said sets of guiding rolls,and wherein said loaf feeding mechanisms are located one higher than theother along said cutting bands.

5. The subject matter of claim 4, wherein the two spaced guiding meansfor said bands comprise a pair of guides for each of said loaf feedingmechanisms.

6. The subject matter of claim 4, including in said loaf feedingmechanisms positive loaf pushing means timed to alternately push theloaves against said cutting bands.

7. The subject matter of claim 4, including in each of said loaf feedingmechanisms endless conveyor means immediately ahead of said cuttingbands, said endless conveyor means having loaf pushers spacedtherearound for successively pushing loaves against said cutting bands,and the loaf pushers on one of said loaf feeding mechanisms beingdisplaced with respect to the loaf pushers on another of said loaffeeding mechanisms to push the loaves against said cutting bandsalternately between the loaf feeding mechanisms.

References Cited in the file of this patent UNITED STATES PATENTS2,143,242 Hartman Jan. 10, 1939 2,569,545 Tatosian Oct. 27, 19512,739,694 Hatch et al. Mar. 27, 1956 2,759,510 Hartman Aug. 21, 19562,827,150 Eaton et a1 Mar. 18, 1958

1. A MACHINE FOR SLICING LOAVES OF BREAD AND THE LIKE, COMPRISING AGROUP OF ENDLESS CUTTING BANDS HAVING TWO SETS OF SPACED GUIDING ROLLS,AT LEAST TWO SPACED GUIDING MEANS FOR SAID BANDS BETWEEN SAID TWO SETSOF ROLLS, THE BANDS BETWEEN SAID GUIDING MEANS BEING SUBSTANTIALLYPARALLEL, AND AT LEAST TWO LOAF FEEDING MECHANISMS ADJACENT SAID CUTTINGBANDS AND HAVING DELIVERY PORTIONS BETWEEN SAID GUIDING MEANS.